I was looking up the 20th-century British sculptor, Dame (Jocelyn) Barbara Hepworth, when I saw this photo of her in the Daily Mail. It was taken in 1970. She died in a fire in her Cornwall cottage, which was also her studio, reportedly because she had been smoking in bed. (Apparently this was similar to the fate of the American actor, Jack Cassidy -- father of Sean and David.) The fire happened in 1975, when she was 72. That means that in 1970, when the photo was taken, she was 66 or 67 (depending on the month). Which is simply amazing. She doesn't look like someone easily under 70. She looks about 108. Never mind booze: that's what the sun will do to you.

Currently reading the National Galleries of Scotland companion to an exhibit called True To Life: British Realist Painting in the 1920s and 1930s. I'm interested in the period, architecturally, culturally, and politically, not to mention the tiles and domestic decorations of the time, so this book will help to round that out. I'm also someone for whom the farther edges of both realism (e.g. any serious botanical or bird artist) and abstraction (e.g. Mark Rothko, Jackson Pollock) have little or no appeal. So-called photorealism raises the question of why not just take a photo -- and the answer is that all art as art selects and distorts, in a different way than the camera does. But the visual effect of photorealism, in which the virtuosity of the illusion is the point, impresses up to that point and then rarely goes farther. On the other hand, an artist whose book is devoted to loose gestural painting, speed of rendering, and vivacity failed entirely to convince me: I preferred the 'before' picture where the round floats on the boats he painted were truly round, and solid like cherries, and had a pleasing density both of colour and form. To my eyes, his looser, more washy version (he works in watercolours) had moved in the wrong direction. To me, there is a sweet spot between too tight and too loose, too precise and too vague. It depends what one is trying to achieve, of course. The economical suggestiveness of Marcia Brown's 'Cinderella' illustrations is admirable. There are as many or more ways to find that sweet spot, and to give it new expression, as there are artists.

To return to the True To Life exhibit: the cover of the book features a striking oil portrait, called 'By The Hills', which was painted by Gerald Leslie Brockhurst and is dated 1939. It features the head of a successful model, actress, and minor aristocrat, and, we are told, the arms of the painter's lover-made-second-wife. Apparently he judged the aristo to be too thin, though given the slimness of the existing arms, and the fact that the aristo was a healthy woman -- she lived till 2002 -- this seems rather unlikely. Anyway, the man was an artist: if her arms lacked sufficient fullness or shape, why not just paint them as he wished them?

Moving on. The face is captivatingly beautiful (even if her eyebrows are too pencil-thin for contemporary taste), but eventually you do look at the head hair rather than just allow it to contribute to the overall impression. And when you do look at the hair, you realize (or I did) that the hair is far less 'realistic' than the face. It looks like a kind of shiny chocolate ganache. In the large and sharp reproduction of the cover photo, the hair looks like something squeezed from an icing bag.

I didn't have all my art supplies with me -- I had to leave much of it at home. So: no pastels, no dry coloured pencils, no artbars, and so on. But I bought a set of art markers and some Prismacolor Verithins, and I made some studies. In particular I studied the nearby trees, taking their 'portrait' more than once, and the stone boy at the water feature (complete with blue cotton sun hat, which someone had placed on his head), and the still life of apple, mineral water bottle, and gin bottle (Tanqueray). What a delightful summer.

Here I'm experimenting with art markers as a way of painting. It was fun, but I'll definitely stick with pencils for the most part!

Here I was paying more attention to the hat.

No. 3 is my favourite of the heads -- it conveys best that this is a stone (or cement) statue.

'The Glorification of the Virgin' by Geertgen tot Sint Jans (most likely) is an astonishing painting, oil on wood panel, that dates to the late 15th century (my Oxford History of Art book, which has this on the cover, gives the date as c. 1480, but the current estimate seems to be the period 1490-1495). The surface has myriad cracks, which in an odd way add to the picture's charm, and certainly to the sense of its antiquity. But honestly, I don't think I've ever seen a more charming and delightful Mother-and-Child picture, not only because of their context -- luminous celestial rings of angel musicians and symbol-holders, a crescent moon to buoy the Madonna up and a little black devil snipping uselessly at her feet -- but also because the faces of both Mary and Jesus are tender, beautiful, innocent, and unfussy in their rendering.

Both mother and child have heads shaped like eggs: if you had to make an egg into a human, this is how you would do it. Even Mary's mantle has much the shape of an egg (with a couple of forward folds like supports to keep the egg upright!). Mary has a wonderful crown: a delicate filigree affair in several colours -- the suggestion of gold, pearls, and enamel for the crown itself, though this is a heavenly crown and has a fairytale character: it has twelve stars, per biblical description. The crown sits atop a cushion of roses (we are told). There are five white roses (how can they count them? -- they look like compressed balls of cotton) for each red one. This is supposed to represent the order of prayers -- five Ave Marias (Hail Marys) and then a Paternoster (Our Father) -- but even if the painting makes reference to the rosary, is it not possible that the number five refers as well to Mary's 'five joys', which are described memorably in the Middle English poem, Sir Gawain And The Green Knight? Just a thought. (The poem is about a century earlier than the painting.)

But in particular, of all the many lovely elements of this picture, what I love best is the baby. He is not the fattest baby Jesus you've ever seen -- one that's already eaten too many pies -- but he's not a stick-figure either. There are photos of me as an infant that look rather similar: a foreshadowing of slimness in maturity. Anyway, the baby squirms and kicks playfully, and reaches out one hand with his 'toy', apparently an open-bottomed bell -- while his other hand holds a second bell out in front of his ear, to be looked at and listened to with interest. This is a baby Jesus not aware so much of his impending doom as of the pleasures of being alive. Even Mary seems to be gazing not just at her son but also at the bell he holds out, as he tinkles along with the music of the heavens (don't forget the angels in the periphery, one of whom rings bells just like the baby's).

It used to be that pencils you could blend using water were 'water-soluble'. But people thought of them as watercolours made with pencils, and 'watercolour pencil' now seems to be the preferred term. It's what's on the tin of my new purchase, 120 pencils -- the complete range of colours -- put out by the German manufacturer, Faber-Castell (in business since 1761!). I love them. They look grand when you just lay the colour down dry, and they're great when you blend them with a paper stump (tightly rolled paper stick with pointed ends) -- and they will no doubt be excellent when I get around to using water. The loveliness of these pencils is that they are so versatile: loaded with pigment, they keep a point well without breaking; and they are beautifully rich even without water added. Here is my try-out picture, of an Envy apple (no water added). Can't wait to explore with these pencils further!

Detail of Mr and Mrs Andrews, c. 1750, oil on canvas -- in The National Gallery, London

Why didn't Thomas Gainsborough finish this work in this precise spot -- it seems complete otherwise -- and what was the splodge on Mrs Andrews' lap intended to represent? Some have suggested 'a baby', but presumably as newlyweds or any rate young marrieds, they did not yet have a baby. Perhaps Gainsborough was leeringly suggesting that he knew a baby would soon 'complete the picture'. On the other hand, does the beige splodge really suggest a baby to you? It looks more like a legless dumpling, and the 'arm' is a puzzler, too. One does not hold a baby with arms arranged as they are in the picture. And what is that strange penis-like outline that bisects the blob? It's much more likely to be a dead pheasant -- one just shot by Mister -- and Mrs has got him by the tail while his wings spread from side to side and his beak points downwards. A highly unlikely scenario: 'Here, wife, I've just shot this bloody bird: dangle it over your silk dress, will you?' It's not only bizarrely unlife-like, it's an insult to the decency and refinement of the lady.

Finally, since the Andrewses evidently didn't like Gainsborough's idea (and who would?), why didn't he paint what they wanted? Why did he leave this strange omission in the middle of an otherwise complete painting? Did he despise them that much? Or perhaps they hated him for making their faces seem charmless and calculating, and for featuring how 'bigly' the land was, by putting them at the edge of the scenery instead of in the middle. And perhaps they thought -- look at the unconvincing hair, the lady's odd eyes, her doll-like unwomanly torso -- that Gainsborough was a naff painter. Perhaps they told him: you're fired.

There are some painterly styles that I have never taken a shine to, and the nudes of Peter Paul Rubens are Exhibit A. I am not terribly fond of Michelangelo's, either, outside of his exquisitely gorgeous sculptures -- and even then, they can be problematic -- 'Night', the female figure in his Julius tomb project, looks like a beautiful male with lumpy breasts clumped on haphazardly over his masculine chest.

But the real effrontery comes not from the lack of a homosexual appreciation of the female form (which, given Michelangelo's staggering mastery of art, is surely the only reasonable explanation for that specific failure), but rather from the work of someone you would expect not only to know better but to sense differently, as well. We are told that Rubens's second wife, a 16-year-old at the time of the wedding, inspired many of his paintings, including The Three Graces, which in his hands is a celebration of cellulite and a study in bodyfat and emergent double chins. The women aren't just fleshy, they're knobbly and bobbly and out of proportion -- his Graces are an abomination of incoherent flab and unintelligible body bulges -- and they have small breasts, so unlikely on fatted-up women! Did the man never lay eyes on a taut smooth-fleshed woman with curves in the right places and feminine muscle? Apparently not. Whatever other attributes this painting has, I can never focus on them because of the repugnance I feel for all the misshapen lard.

One side... with two like bottoms on the other. Roman copy of a Greek sculpture, Metropolitan Museum of Art, New York

That said, the gamine and rather characterless Graces painting that was once owned by Adolf Hitler is a step in the other direction: apart from the difficulty of assessing any art created with Nazi sanction, the women look too much like approved specimens for breeding who are presenting themselves to their masters' gaze. One wonders what would happen should they ever put on a pound or two -- or ever want a livelier, less airless atmosphere.

Fortunately, there is a middle way of perfection between the taut and the dysmorphic, and that can be found in ancient sculptures, but also more recently in the work of 19th-century artists, who knew what a fine figure consists in and could represent them without sinister undertones. Indeed, Antonio Canova gave us Three Graces who are inspirations to each other, and might just as well be unaware of the viewer: it is a sisterhood and mutual admiration society, and we look on without their asking our applause or approval. I think this works as a visually more intricate spectacle, but it also says something about the nature of the graces or goddesses themselves, since their qualities begin from within even though they might also have outward expression. The sculpture gives tangible form to the truth that no single quality is complete in itself, but gains from embracing others as well. Canova gives us girls that are slender without being hard, shapely without being excessively voluptuous, and charmingly charmed by their own charms. And even better, they are all smooth, the convention for refusing to sculpt female pubic (or axillary) hair holding strong. Who cares if the bottoms are ever so slightly droopy?